Flaps (2.5)

2.5 hours

Today I got the RH flap skin cut out.  It took me a little while to figure out the compound angles that the plans called for!

I cut the skin with snips.  I've seen people do it with a band saw or miter saw, but I didn't feel like setting up any power tools.  The flap skins come in 72" pieces, but I'm doing the Sport Acro setup so the longest part of the flaps are only 54.5".  I started by cutting the piece down to 56" long to make it more manageable.  It's a pain to cut through the middle of a sheet with snips, but once you get close to your line it gets real easy to cut accurately.

A full 72" piece of skin material.

Precision is the name of the game!!!  This was my extremely rough cut to within a couple inches of the final length.

Cutting the final size.

Sheet metal is sharp; be careful not to add too much extra character to your workbench!

Once I had the RH skin cut, I started laying out the ribs.  These shortened flaps only get three ribs each, including the drive ribs.  I laid out the holes and drilled the outboard and center ribs, but I noticed the dimension locating the inboard (drive) rib didn't look right.  The dimension didn't quite line up with where the rib was actually depicted in the drawing.  I called Sonex about it, and Kerry said it's probably not correct, but they'll have to get back to me with the correct dimension.  I called it a day at that point!

This 50-23/32" dimension is supposed to locate the drive rib, but it doesn't actually line up with where the rib is.  Chances are that means it isn't right!

Flap & Aileron Parts, Part 2 (6)

6 hours

More control surface parts!  I asked Sonex about those CCC-34 rivets that are called out to attach the nutplate to each flap drive rib.  Turns out it was a typo, and it was supposed to be SSC-34's which I do have!  They came with the hydraulic brakes kit.  I also noticed that I was supposed to countersink all the holes on the flap drive ribs and use flush rivets.  So good thing I hadn't gone ahead and riveted it yet.

I picked up this microstop countersink, and it's great.  It took a few minutes so set up, but once it was set I was able to knock out all the countersinks pretty fast, and they are consistent!

I also found that if I drilled the through hole for the nutplate up to 3/16" on the rib, I could use a cleco to hold the nutplate in place so I could transfer the two mounting holes.  After that, I updrilled the hole to 17/64", which as far as I know is the proper clearance hole size for a 1/4" bolt.

Anyway, now these two parts are finally done!

Aileron drive ribs also done!

These two channels were tricky to rivet because the holes are so close to the flange.

Not a big deal, I just ground some more material off of my low profile rivet puller!

This poor thing is probably going to break any time now as I keep shrinking it, but for now it works great!

Next was the aileron counterweight assemblies.  The kit comes with a 1" thick block of lead, which just needs to be cut in half to produce the two weight blocks.  I cut it on the bandsaw, which was actually really easy.

With those two things ready, I just had to build the assemblies to go with them.  I used some tabletop geometry to locate the first rib on it's corresponding plate.

Once that was set I transferred a few holes from the plate to the rib, and then clamped that rib to its opposing rib and transferred the holes to it.  That took care of locating all the parts on the first assembly.

Then I took each rib off and transferred the holes again to the other opposing rib, to create two identical pairs.

With everything now located, I just had to transfer the rest of the holes, updrill, deburr, and rivet!

The next step was drilling the lead blocks in between the plates.  This was not as easy!  I found that once the drill bit started cutting it would get sucked in real quick and then either get stuck or just break.  After snapping a couple of #40 bits I started the rest of the holes on #30, which worked a little better.  I probably could have started even larger.  Anyway I eventually got all the holes up to 3/16".  Then I took them apart to deburr and scrape off the chunks of lead that were wedged between the plates.

I had to hammer the crap out of these bolts to get them through the lead!

Done!

 I think between these six little parts I pulled almost 200 rivets, so if they say this kit is around 10,000 rivets that's like 2% right there!

Flap & Aileron Parts (3)

3 hours

I'm starting on the flaps and ailerons now, beginning with the drive ribs for each surface.

Flap drive rib parts

Flap drive ribs coming together

The flap drive ribs each get a nutplate which calls for two CCC-34 rivets, which I do not have on hand.  I'll have to get my hands on some before I can finish these parts!

Flap drive ribs ready to rivet once I get the nutplates installed.

Aileron drive ribs in progress

Flap and aileron drive ribs, plus two little channels that will be part of the aileron counterweights ready to rivet.

Cover Plates (0.5)

0.5 hours

I got these cover plates done.  Very easy!

Left Main Spar Part 2 (0.5)

0.5 hours

I got the last few parts attached, so until I mate the two spars the left side is done!

Left Main Spar (3)

3 hours

Cranking away on the left main spar.  Since I already did most of this on the right spar this went pretty fast!  It's just about done, I just need to bolt down the outboard vertical stiffener and tiedown fitting, and rivet the tip rib angle and it'll be all done!

These 8 bolts were still kind of a pain to torque down, but it went faster than the right side did.

The holes on the root rib attach angles don't quite all line up with each other, so I clamped them together and drilled through both using the aft angle as the master.  Then I used the aft angle to transfer the holes to the spar web.  Once the holes were all enlarged to 3/16" they lined up just fine.  On the right side, I tried to do all this with the angles clamped to the spar and it was a pain.  This worked much better!

Root rib attach angles and wing attach block done!

Rear Wing Spars Done (1)

1 hour

Now that I have my hardware I was able to put the last two bolts in each rear wing spar assembly.  I did run into a small problem that I kind of expected, and that was the bolt holes in the root rib attach angles were too close to the radius of the angle for a nut to sit flat.

Not a big deal, I just had to whip up four little blocks with a rounded edge, and use longer bolts.  I'm pretty sure the legacy Sonex/Waiex plans have you do this anyway, but they aren't called out on my B-model drawings.  If you flip to the page where it shows the root ribs attached to the rear spars though, they still show up.

See how the nut can't sit flat because the radius is in the way.

Here's one spacer done.

Another example.  I swapped out the AN3-5A bolts for -7A's to make up for the extra thickness.

Done!

Here's a diagram later in the build process, and you can see the blocks I just built shown here!